The present invention relates in general to fairings or doors for aircraft landing gear, and in particular to a landing gear door which dually serves as a fairing and a splash guard against debris thrown up from the wheels.
A persistent problem with deploying aircraft from wet or muddy runways or unpaved surfaces of dirt, grass or gravel is the tendency of the wheels to throw up mud, rocks and other debris which can cause damage to engine inlets, radomes, flaps and fuselage skinning. Various prior art constructions have been designed in an attempt to alleviate this problem.
One such design is found in U.S. Pat. No. 3,670,996, issued to Jenny. The Jenny deflector consists essentially of a plate which remains in a horizontal position both when the landing gear is extended and retracted. A disadvantage of the Jenny design is that the deflector plate is completely separate from the fuselage, and must be precisely positioned over the wheel well to function efficiently as a fairing. Furthermore, complex linkages are required to position the plate around the extended landing gear, and the area of the plate must be rather large in comparison with the wheel.
By pivotally connecting the wheel well door to the airframe, an efficient fairing, i.e., one that presents a minimum of air resistance due to discontinuity between the fuselage and door surfaces, may be constructed. Examples in the prior art are U.S. Pat. Nos. 1,890,902; 1,894,582; 1,956,313; and 2,129,824 issued to Douglas; DeBell, Capelis; and de Seversky respectively. The Douglas and Capelis fairings, which both include sections positioned behind the wheel, offer the potential of serving as splash guards. However, neither these nor any other prior art references suggest means by which the clearance between the door and the ground or runway surface may be controlled.
Control of the ground clearance is necessary because landing gear shock struts allow considerable movement of the wheels with respect to the airframe. Thus, a door positioned behind the wheels and spaced sufficiently close to the ground to deflect mud, stones, etc. from the wheels when the shock strut is fully compressed will be too far from the ground to intercept debris when the shock strut is extended. Conversely, of course, if the clearance is correctly set for an extended strut, compression of the shock strut would result in the door dragging on the ground.